RU2553576C2 - Clinker-free binder - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention relates to construction materials, particularly, to binders and can be used for production of dry construction mixes, mortars and concretes as well as other construction materials. This binder comprises the following components: annealed at 800-900°C mix of magnesium-bearing carbonates and clays, magnesium sulphate and mineral additive, i.e. zeolite-bearing carbonate-silicic rock, plasticising agent SP-1 and gardening promoter, i.e. sodium sulphate, at the following ratio of said components, wt %: said mix - 58-85, magnesium sulphate - 3-6, zeolite-bearing carbonate-silicic rock - 10-30, plasticising agent SP-1 - 1-2, sodium sulphate - 1-4. Note here that magnesium-bearing carbonate rock-to-clay ratio makes (2.7-10):1.

EFFECT: higher strength under normal conditions.

2 cl, 2 tbl

Description

The invention relates to the field of building materials, in particular binders, and may find application in the construction industry for the manufacture of dry mortar, mortar and concrete, as well as other building materials, which include binders.

Known clinker-free hydraulic binder based on carbonate-clay raw materials, including hydraulic lime, consisting of marl lime calcined at a temperature of 900-1100 ° C, containing up to 25% clay impurities (A.V. Volzhensky, Yu.S. Burov, V.S. Kolokolnikov Mineral binders. - M .: Stroyizdat, 1979, p.135-140).

The disadvantages of a binder based on hydraulic lime are: low strength, slow hardening rate, low softening coefficient.

Known clinker-free hydraulic binder based on carbonate-clay raw materials, including romance, consisting of marls, calcined at a temperature of 800-1100 ° C, containing 25-35% clay impurities (A.V. Volzhensky, Yu.S. Burov, V.S. Kolokolnikov Mineral binders. - M .: Stroyizdat, 1979, p.140-143).

The disadvantages of a cement-based binder are: low strength, slow hardening speed, low softening coefficient.

It is also known astringent, including hydraulic lime from silica-containing limestone and a filler from silica-containing limestone at a content in wt.%:

hydraulic lime 23-39%;

filler 61-77%;

Properties: compressive strength 11.5-25.1 MPa;

water resistance 0.83-0.98;

(see RF patent 2023697 class C04B 7/34, bull. No. 22, 11/30/94).

The disadvantages of this binder are: the limited MgO content (up to 1.09%) in the binder and, therefore, the inability to use hydraulic lime from magnesium-containing carbonate rocks (dolomitic limestones and dolomites), which narrows the raw material base, low strength and water resistance under normal hardening conditions, which does not allow the use of a binder for the manufacture of mortars and concrete in ordinary conditions.

The prototype for the claimed invention is a binder containing a mixture of magnesium-containing carbonate rocks with clay calcined at a temperature of 800-900 ° C at a ratio of (3-9): 1, as a mineral additive - waste from the production of a metallurgical plant - blast furnace granulated slag fractions of 0.01- 0.08 mm and magnesium sulfate in the following ratio of components, wt.%:

a mixture of magnesium-containing carbonate rocks and clay 60-85 granulated blast furnace slag 10-30 magnesium sulfate 5-10

(see RF patent 2255063 C. C04B 7/34, Bull. No. 18.27.0.05).

The disadvantage of this binder is its low strength.

The objective of the invention is to increase the hardening strength under normal conditions.

The result is achieved in that the binder, including a mixture of magnesium-containing carbonate rocks and clay burnt at a temperature of 800-900 ° C, magnesium sulfate and a mineral additive, according to the invention contains as a mineral additive a zeolite-containing carbonate-siliceous rock and, in addition, an SP-1 plasticizer and an accelerator hardening sodium sulfate in the following ingredients in the mass. %:

specified mixture 58-85 magnesium sulfate 3-6 zeolite-containing carbonate-siliceous rock 10-30 plasticizer 1-2 hardening accelerator 1-4

The result is also achieved by the fact that the binder contains as a plasticizer: SP-1, as a hardening accelerator: sodium sulfate.

The result is also achieved by the fact that the ratio of magnesium-containing carbonate rocks and clay is (2.7-10): 1.

A binder was prepared by mixing the components in a ball mill.

To obtain a binder, the following components were used:

- clay, for example, Koshchakovo field RT of the following composition in wt.%: SiO ₂ - 68.47; Al ₂ O ₃ - 13.17; Fe ₂ O ₃ - 5.76; CaO - 1.65; MgO - 1.91; K ₂ O - 1.67; TiO ₂ 0.78; SO ₃ - 0.06; Na ₂ O - 0.37; P ₂ O ₅ - 0.13; MnO - 0.1; loss on ignition - 5.51;

- magnesium-containing carbonate rocks with MgO content up to 20% according to OST 21-27-76 "Carbonate rocks for the production of building lime. Technical conditions";

- mineral additive: zeolite-containing carbonate-siliceous rock TU 5743-002-020069662-96;

- magnesium sulfate TU 2141-025-32496445-01;

- plasticizer SP-1 TU 5870-005-58042865-05;

- hardening accelerator: sodium sulfate TU 2141-114-05766575-2004 rev.2;

To obtain binder samples, we used: a mixture of magnesium-containing carbonate rocks of the Matyushinsky field of the Republic of Tatarstan, clay of the Koshchakovsky field of the Republic of Tatarstan, zeolite-containing carbonate-siliceous rock of the Tatarsko-Shatrashansky field of the Republic of Tatarstan.

The mixture was obtained by roasting at a temperature of 800-900 ° C of a mixture, ground to a state of flour, consisting of magnesium-containing carbonate rocks and clay with a ratio of (2.7-10): 1, followed by grinding to a specific surface of 300-350 m ² / kg.

The composition of the mixture in wt.%:

Cao active 0-20 MgO active 5-15% (3C ₂ S, CA, CAF) rest

The zeolite-containing carbonate-silica rock was dried and milled until it passed through a 008. Screen. The magnesium sulfate was dried and dehydrated.

When binder is mixed with water, calcium silicates and aluminates are hydrated, and at the same time, free CaO forms calcium hydrosilicates and hydroaluminates with minerals of a zeolite-containing carbonate-siliceous rock, thereby increasing strength and water resistance.

The plasticizing additive reduces the amount of mixing water, forming an adsorption layer on the surface of the solid phase, causes a change in the electrokinetic potential and, as a result, an increase in electrostatic repulsive forces, decomposition of aggregates and the release of water mobilized in floccules, increasing the hardening speed and strength.

Magnesium sulfate increases the solubility of MgO, promotes its hydration and the formation of magnesium oxyhydrosulfates, which compact the structure of cement stone and increase strength and water resistance.

Sodium sulfate, reacting with calcium oxide hydrate, forms gypsum. The resulting finely divided gypsum reacts with minerals and contributes to a more rapid crystallization of tumors from the cement gel.

The zeolite-containing carbonate-silica activates the silicate and aluminate phases of the binder, helps to accelerate the hydrolysis and hydration of clinker minerals and a quick set of strength of the binder in the early stages of hardening, and further increases the strength by effectively binding lime under normal hardening conditions.

To test the binder compositions, samples were prepared from the mortar mixture with sand in the ratio binder: sand = 1: 3 with a water-cement ratio of 0.4. Tests of the basic properties of the binder were carried out in accordance with GOST 30744. The data on the compositions are shown in table 1, and the characteristics of the binder in table 2.

Table 1 Composition number mixture composition, m.h. The amount of the specified mixture in a clinker-free binder,% The content of additives,% Magnesium sulfate Zeolite-containing carbonate-siliceous rock SP-1 Sodium sulfate one 2.7: 1 85 3 10 one one 2 2.7: 1 72 4,5 twenty 1,5 2 3 2.7: 1 58 6 thirty 2 four four 6.4: 1 85 3 10 one one 5 6.4: 1 72 4,5 twenty 1,5 2 6 6.4: 1 58 6 thirty 2 four 7 10: 1 85 3 10 one one 8 10: 1 72 4,5 twenty 1,5 one 9 10: 1 58 6 thirty 2

table 2 Composition number Compressive strength MPa Bending Strength, MPa Volume uniformity one 34.2 3.2 Sustained 2 35,4 3.4 Sustained 3 33.8 3.3 Sustained four 32,3 3,1 Sustained 5 31.6 3.0 Sustained 6 31,0 3.0 Sustained 7 29.7 2.9 Sustained 8 29.5 2,8 Sustained 9 29.2 2,8 Sustained prototype 28.1 2,8 Sustained

Analysis of the data obtained as a result of binder tests shows that it meets the intended purpose: it has strength characteristics higher than that of the prototype, the composition with the lowest strength provides strength higher than the optimal composition of the prototype. The expansion of the raw material base through the use of local magnesium-containing raw materials is also achieved.

Claims (2)

1. Clinker-free binder, including a calcined mixture of magnesium-containing carbonate rocks and clay, magnesium sulfate and a mineral additive, characterized in that as a mineral additive contains a zeolite-containing carbonate-siliceous rock and additionally a plasticizer SP-1 and an accelerator of hardening sodium sulfate in the following contents of ingredients in mass%:
specified mixture 58-85 magnesium sulfate 3-6 zeolite-containing carbonate-siliceous rock 10-30 SP-1 1-2 sodium sulfate 1-4 2. Clinker-free binder according to claim 1, characterized in that the ratio of magnesium-containing carbonate rocks and clay is (2.7-10): 1.